Research on surface topography of MEMS micromirror based on 3D Weierstrass-Mandelbrot function

摘要

Micro-mirror is the key structure of MEMS optical switch, Digital Mirror Display (DMD) and variable optical attenuators. Surface roughness plays a crucial rule in reflectivity, insertion loss, and all kinds of surface forces. In this paper, a silicon based non-silicon MEMS optical switch is fabricated and the topographies of various micro-mirror surfaces are measured by Scanning Tunneling Microscope (STM). After fractal analysis, a three-dimensional Weierstrass-Mandelbrot function is applied to simulate the topography of different surfaces. The result shows that the surface of MEMS micromirror which fabricated by metal sputter has low anisotropism and the W-M function is very efficient in creating models and is very useful in analysis the topography of MEMS surface.